Composite part resin infusion with dynamic thickness control

Abstract

Systems and methods are provided for fabricating composite parts. One embodiment is a method of fabricating a composite part. The method includes providing a preform on a tool mandrel, positioning sensors around the preform according to a target shape of the composite part, and sealing the preform with a vacuum bag to form a chamber. The method also includes applying temperature and pressure to the chamber to infuse a resin into the preform to create a composite preform undergoing infusion, monitoring a thickness of the composite preform prior to completing cure, and adjusting at least one of the temperature and the pressure prior to completing cure based on the thickness.

What is claimed is: 
     
       1. A method of fabricating a composite part, the method comprising:
 providing a preform on a tool mandrel; 
 positioning sensors around the preform according to a target shape of the composite part; 
 sealing a vacuum bag to the tool mandrel to form a chamber containing the preform; 
 applying pressure to the chamber in a manner causing resin to infuse the preform to create a composite preform undergoing infusion; 
 monitoring, using the sensors, measurement values of a thickness of the composite preform during at least one of the following: during infusion of the composite preform, during curing of the composite preform, and during a transition period between infusion and curing; 
 analyzing the measurement values of the thickness relative to historical data of prior composite part fabrications, to predict if a cured thickness of the composite part resulting from curing of the composite preform, would fall outside of a tolerance range specified for the composite part; and 
 adjusting, if it is predicted that the cured thickness of the composite part would fall outside of the tolerance range, the pressure applied to the chamber during curing of the composite preform, in a manner causing the cured thickness of the composite part to fall within the tolerance range. 
 
     
     
       2. The method of  claim 1  further comprising:
 adjusting the pressure after the infusion and before the curing, in a manner ensuring that the cured thickness of the composite part will fall within the tolerance range. 
 
     
     
       3. The method of  claim 1  further comprising:
 positioning the sensors around the preform at locations where the cured thickness of the composite part is to be verified. 
 
     
     
       4. The method of  claim 1  further comprising:
 controlling the cured thickness of the composite part via adjusting the pressure in a manner to produce the composite part as a cured part having a predetermined cross-sectional thickness. 
 
     
     
       5. The method of  claim 1 , wherein analyzing the measurement values further comprises:
 calculating adjusted values for at least one of a heat and the pressure to apply to the chamber. 
 
     
     
       6. The method of  claim 5  further comprising:
 calculating the adjusted values based on a correlation in the historical data between physical characteristics of composite preforms and a cured thickness of the prior composite part fabrications. 
 
     
     
       7. The method of  claim 5  further comprising:
 calculating the adjusted values based on a correlation in the historical data between physical characteristics of the composite preform and a cured thickness of the prior composite part fabrications, the physical characteristics including one or more of a resin age, a resin mixture process, and a resin production source. 
 
     
     
       8. The method of  claim 5  further comprising:
 providing the measurement values to a controller, the measurement values including one or more of the thickness, a measured temperature of the chamber, a measured pressure of the chamber, a measured viscosity of the resin in the composite preform, and a time; and 
 calculating, with the controller, the adjusted values for at least one of the heat and the pressure to apply prior to completing cure based on the measurement values and a correlation in the historical data between one or more prior measurement values and a cured thickness of the prior composite part fabrications. 
 
     
     
       9. The method of  claim 8  further comprising:
 providing characteristics of the resin used in the infusion to the controller; and 
 calculating the adjusted values for at least one of the heat and the pressure to apply prior to completing cure based on the characteristics of the resin and the correlation in the historical data. 
 
     
     
       10. A method of fabricating a composite part, the method comprising:
 providing a preform on a tool mandrel having a resin reservoir containing a resin; 
 positioning sensors around the preform; 
 sealing a vacuum bag to the tool mandrel to form a chamber containing the preform and the resin; 
 applying pressure to the chamber according to a profile of pressure applied using a vacuum pump; 
 infusing the resin into the preform according to the profile of pressure applied to the chamber applied using the vacuum pump; 
 monitoring, using the sensors, a thickness of the preform during at least one of the following: during infusion of the composite preform, during curing of the composite preform, and during a transition period between infusion and curing; 
 analyzing the thickness of the preform relative to historical data of prior composite part fabrications, to predict if a cured thickness of a composite part resulting from curing of the preform, would fall outside of a tolerance range specified for the composite part; and 
 adjusting, if it is predicted that the cured thickness of the composite part would fall outside of the tolerance range, the profile of pressure applied to the chamber via the vacuum pump during curing of the composite preform, in a manner causing the cured thickness of the composite part to fall within the tolerance range. 
 
     
     
       11. The method of  claim 10  wherein:
 the historical data correlates one or more of a resin age, a resin mixture process, and a resin production source with a cured thickness of prior composite part fabrications. 
 
     
     
       12. The method of  claim 10  wherein:
 the historical data correlates a resin viscosity with a cured thickness of prior composite part fabrications. 
 
     
     
       13. The method of  claim 10  wherein:
 the historical data correlates one or more of a measured temperature, a measured pressure, a measured viscosity of the resin, and a time with a cured thickness of prior composite part fabrications. 
 
     
     
       14. The method of  claim 10  further comprising:
 positioning the sensors around the preform at locations where the cured thickness of the composite part is to be verified. 
 
     
     
       15. The method of  claim 10 , wherein analyzing the thickness of the preform further comprises:
 generating a notification that the predicted cured thickness of the composite part is outside of the tolerance range. 
 
     
     
       16. The method of  claim 10 , wherein analyzing the thickness further comprises:
 calculating adjusted values for the profile of pressure to apply to the chamber. 
 
     
     
       17. A composite fabrication system comprising:
 a tool mandrel configured to support a preform of fiber layers; 
 a vacuum bag configured to be sealed to the tool mandrel in a manner forming a chamber containing the preform; 
 a pressure source configured to apply a pressure to the chamber; 
 a resin supply configured to supply the resin to the preform via the pressure applied to the chamber to cause the resin to flow into the preform to thereby infuse the preform, wherein infusion of the resin into the preform creates a composite preform undergoing infusion; 
 sensors disposed around the preform according to a target shape of a composite part, and configured to generate measurement values of a thickness of the composite preform during at least one of the following: during infusion of the composite preform, during curing of the composite preform, and during a transition period between infusion and curing; and 
 a controller configured to:
 analyze the measurement values of the thickness relative to historical data of prior composite part fabrications, to predict if a cured thickness of the composite part resulting from curing of the composite preform, would fall outside of a tolerance range specified for the composite part; and 
 adjust, if it is predicted that the cured thickness of the composite part would fall outside of the tolerance range, the pressure applied to the chamber during curing of the composite preform, in a manner causing the cured thickness of the composite part to fall within the tolerance range. 
 
 
     
     
       18. The composite fabrication system of  claim 17  wherein: the historical data correlates one or more of a resin age, a resin mixture process, and a resin production source with a cured thickness of the prior composite part fabrications. 
     
     
       19. The composite fabrication system of  claim 17  wherein: the historical data correlates a resin viscosity with a cured thickness of the prior composite part fabrications. 
     
     
       20. The composite fabrication system of  claim 17  wherein:
 the sensors are disposed at locations where the cured thickness of the composite part is to be verified.